Bell Furnace

Bell Furnace


a batch-operated heat-treatment furnace in which products are heated under a movable dome. It is used for heat treatment of sheet and light-section rolled products in a controlled gaseous medium. Bell furnaces are classified according to use (treatment of coils of narrow strip, sheets, rods, and so on).

The most common bell furnaces are the single-stack and multistack types used for annealing coils of cold-rolled steel strip. In multistack bell furnaces, three to eight stacks, each of which has its own muffle for protection against the effects of the hot air and products of combustion, are mounted on a rectangular stand under the heating dome. Each stack is 3–5 m high and contains three to five coils with a total weight of up to 180 tons. The dome is heated by gas or electrical resistance heaters. Upon completion of the heating process, the dome is transferred by crane to another stand and the products are left to cool under the muffles on the first stand. Heat exchange under the muffle is intensified by forced circulation of controlled gas. Cooling is accelerated by wetting the muffle with water or blowing cold air over it.

During treatment in a bell furnace the coils of strip are loose, with spaces between the coil loops so that the gas circulates between the loops and flows over the entire surface of the strip, which makes possible thermochemical treatment and acceleration of heating and cooling.


Apterman, V. N., E. G. Dveirin, and V. M. Tymchak. Kolpakovyepechi. [Moscow] 1965.
Spravochnik konstruktora pechei prokatnogo proizvodstva. Edited by V. M. Tymchak. Moscow, 1970. Chapter 33.


References in periodicals archive ?
Bell furnace for debinding us sintering of oxygen-permeable, tubular membranes in a quantity of 50 pieces / fire, an end length of 1000 mm, optional lying or hanging up to a maximum temperature of 1450 A C under an inert protective gas flushing (nitrogen) with change on air after debinding.
The bell furnace can heat and cool up to 30 tons of semi-finished steel strip at a time, of any thickness, to provide requisite hardness.
Contract notice: Bell furnace to 1500 A c for the simultaneous removal of the binder and sintering of oxygen-permeable membranes in an inert gas / air pressure.